xenharmonic (microtonal wiki) - SpiralProgressions

If you're on:	For downward spiral, move thus:	For upward spiral:
5th	up 2 dieses	up 3 dieses
3rd	stay	down 2 dieses
root	down 3 dieses	stay

Decide on downward (C-E-G#-B#) or upward (C-Ab-Fb-Dbb) root movement. We found downward easier almost every time.
Sing a just major triad (4:5:6), any inversion, open or closed spacing. Tune and match vowel to lowest voice.
Move in accordance with the chart. Since two people are moving each time, make eye contact to synchronize the change.

After three moves, you will have the same triad one diesis up or down. Keep going if you can!

recording on [u]: